quantity_parametric.Rd
For a parametric distribution, evaluates a quantity
(such as mean, median, range, ...) if the distribution has
an entry in the .quantities
database. For distributions without
the "parametric" (sub-) class, quantity evaluation is delegated
to the next higher level class.
quantity_parametric(distribution, quantity)
A distribution.
Character; name of the quantity to extract.
The desired quantity, evaluated.